#1036 setting IsFocusEngagmentEnable

Author: IbraheemOsama

Microsoft.Toolkit.Uwp.UI.Controls/GridSplitter/GridSplitter.Events.cs

@@ -45,7 +45,7 @@ private void GridSplitter_Loaded(object sender, RoutedEventArgs e)
 
             Element = gripper;
 
-            KeyDown += Gripper_KeyDown;
+            gripper.KeyDown += Gripper_KeyDown;
 
             var hoverWrapper = new GripperHoverWrapper(
                 CursorBehavior == SplitterCursorBehavior.ChangeOnSplitterHover

Microsoft.Toolkit.Uwp.UI.Controls/GridSplitter/GridSplitterGripper.cs

@@ -46,8 +46,9 @@ internal GridSplitterGripper(GridSplitter.GridResizeDirection gridSplitterDirect
             ResizeDirection = gridSplitterDirection;
             HorizontalContentAlignment = HorizontalAlignment.Stretch;
             VerticalContentAlignment = VerticalAlignment.Stretch;
-            //IsTabStop = true;
-            //UseSystemFocusVisuals = true;
+            IsTabStop = true;
+            UseSystemFocusVisuals = true;
+            IsFocusEngagementEnabled = true;
         }
 
         internal GridSplitterGripper(